>>2524693a 4 weight with the right leader can present everything from #4 streamers to #24 dry flies. i would actually go the other way with fly gear, since it is so light, you can generally stand going a size or two heavier.
the main advantage with getting a 4 over a 3 is you'll have a little easier time casting in wind, you'll have a little more backbone for bass and bigger trout. as for a 3 weight, the advantages you get are slightly gentler presentation and small fish fight better, a situation that a 2 weight handles better yet still. i've always been a proponent to picking either even or odd. the difference between a 3 and 4 weight is almost negligable but the difference between a 3 and 5 weight is enough to make them distinct tools, for example.
